The aim of the study was to determine the microbiological profile of acute appendicitis in children. Prospective descriptive study including children hospitalized for acute appendicitis. A specimen of the appendice and the peritoneal exudates (if exists) was performed intraoperatively for aerobe bacteriological examination. Anaerobic incubation was not possible in our study. Eighty children were included. The specimen culture isolated aerobic bacteria in 56 patients (70%). Polymicrobial infection was found in 14 children. Gram-negative bacilli were the most frequently isolated microorganisms (64/70). Escherichia coli was found in 48 children. The resistance rate to amoxicilline-clavulanic acid and to cefazolin was 35%. Pseudomonas aeruginosa susceptible to ticarcillin was detected in seven patients. In our study, the specimen culture found aerobic bacteria in 70% of cases, especially Gram-negative bacilli. Empiric antibiotherapy in acute complicated appendicitis in children should be efficient against these microorganisms.